Muscle development device



FIG. 1 is a perspective view of a muscle development device showing my new design thereof;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is another perspective view of a muscle development device of FIG. 1. 

CLAIM The ornamental design for a muscle development device, as shown and described. 